AIR SAMPLING INSTRUCTIONS
The basic objective of air sampling is to capture a sample of the contaminants present within the
air in the workplace. There are three principle types of air sampling methods in use. These
methods are, active, grab and passive sampling. Active sampling involves the use of
mechanical pumps and other air collection devices. Grab sampling is an active method which is
used most often to determine worst case conditions and/or identify emission source locations or
“hot spots.” Passive sampling is a method based on the natural tendency of gas or vapor
molecules to move from an area of high concentration to one of lower concentration. Active,
Passive and Grab sampling methods will be addressed in detail in these instructions.

I. ACTIVE SAMPLING:

Active sampling consists of the collection of a known volume of air and depositing of the

contaminant being investigated upon the appropriate collection medium. The Travelers Air

Sampling Guidelines have been published for your use in determining the appropriate air

sampling method for specific contaminants.

To determine full-shift employee

exposure levels to chemicals in

the workplace, it is necessary to

evaluate the Time-Weighted

Average (TWA) contaminant

concentration. Integrated

sampling methods using

rechargeable, battery-powered,

personal sampling pumps are

used for TWA sampling.

Travelers supplies rechargeable,

battery powered, personal

sampling pumps. The pumps

operate over a wide range of

flow rates and are suitable for

evaluating most airborne chemical exposures encountered in the workplace. The pumps

provide a measured air flow for time periods of up to a full work shift, and are of a size and

weight to be considered portable.

Attaching the Pump to the Employee:

Integrated sampling involves the attachment of a sampling train to the employee. The sampling

train normally consists of the pump, appropriate flexible tubing, the media (tube/filter), and any

necessary media holder.

Gilian pumps are equipped with a wide metal clip intended to hold the unit securely on the

employee’s belt or waist band. The media should be placed on the employee’s shoulder or

lapel within several inches of his or her chin in an area called the “breathing zone.” The

breathing zone is defined as an imaginary 9 inch sphere around a person’s head. These

breathing zone samples are considered to represent the employee’s actual exposures. Since

placement of the sampling media can be critical, it should be located as close as possible to the

employee’s face.

Care should be taken to minimize the possibility of the tubing catching on workplace objects or

interfering with the employee’s work. In general, placing the pump on the employee’s left or

right hip routing the tubing diagonally across the back (either under the right or left arm or over

the right or left shoulder) to the breathing zone seems to be the best arrangement.

air sampling of gases

AIR POLLUTION MONITORING

 

Introduction

The Air (prevention and control of pollution) act, 1981 has in its preamble, the objective to take “appropriate steps for the preservation of the natural resources of the earth, which among other things, include the preservation of quality of air.”  The preservation of quality of air means the fixing up of certain minimum standards of ambient air quality in respect of the common and uncommon ingredients of air and the prevention of increase of the concentration of such ingredients in comparison to the fixed minimum quality.

These are many ingredients which may be termed as “primary pollutants.”  These are five primary pollutants which together contribute more than 90% of global air pollution.  These are :

A.          Carbon monoxide, CO

B.          Nitrogen oxides, NO₂

C.          Hydrocarbons, HC

D.          Sulphur oxides, SO₂

E.          Particulates

After being released directly into the atmosphere, these primary pollutants react with atmospheric constituents and with themselves and thus produce secondary pollutants.  In many situations these secondary pollutants are much more dangerous and injurious to the environmental quality.  One of the most common secondary pollutants is ‘Photochemical Smog.’

The preservation of air quality requires constant and continuous monitoring of the ambient air and effective control measures to reduce the emissions from anthropogenic sources.  This also requires efficient methods to forecast the future ambient air quality and implementation of such schemes which may monitor and respond quickly and effectively to control episodal and emergency emissions.  Thus, we may agree that the data collection and their interpretation play very important role in the ambient air quality preservation.  Here, we shall be mainly concentrating on the sampling procedure for various air pollutants.  We shall also discuss difficulties encountered in collecting representative samples and sources of error.  The methods used for measuring gaseous emissions from a stack or a vent depend on the nature of the compound and the purpose for making the measurement.  In addition, the composition and the temperature of the carrier gas stream affect the selection of a sampling technique, analytical method and sampling plan.

Classification of Sampling Methods

The sampling methods used for the study of air pollution can be classified under three different headings.

1.      Sampling of impurities of various nature (ranging from particulate matter to gases).

2.      Sampling under various environmental conditions (ranging from samples taken from chimneys to samples taken in the open air).

3.      Sampling methods varying according to the time factor (ranging from intermittent to continuous sampling).

Difficulties Encountered in Sampling

1.      Collecting samples of true representative character.

2.      Errors arising from methods used for the collection and separation of the various components of pollution.

3.      Difficulty in preventing any change in the concentration of particulate matter in suspension, as a result of sampling operations.

Instruments for Sampling Waste Gases and the Atmospheric Sampling

Following are the sampling devices in use:

Devices for General Use

Meters

They are used to determine accurately the volume of the gas collected.  They are fitted with manometers and thermometers to indicate the pressure and temperature of the gas stream sampled.

Probes

These are tubes suitable for penetrating into the gas stream and should be constructed of materials which are non-corrosive and which can withstand special temperature conditions.  Also, they should be constructed of materials which do not react with the substances to be sampled.  Therefore, they should be made of stainless steel or preferably of glass or quartz.  A probe should have suitable length and diameter.  To ensure isokinetic sampling conditions, the opening of the probe should face the gas stream to be sampled.

Suction Devices

Any suction device which has the required volumetric capacity can be used.  Vacuum pumps driven by electric motors are very commonly used.

Devices for Sampling Gases and Vapours

Absorbers

In this process, effluent gases are passed through absorbers (scrubbers) which contain liquid absorbents that remove one or more of the pollutants in the gas stream.  The efficiency of this process depends on –

(1)     amount of surface contact between gas and liquid

(2)     contact time

(3)     concentration of absorbing medium

(4)     speed of reaction between the absorbent and gas

Absorbents are being used to remove sulphur dioxide, hydrogen sulphide, sulphur trioxide and fluorides and oxides of nitrogen.

The equipment using the principle of absorption for the removal of gaseous pollutants includes :

(1)     packed tower,

(2)     plate tower,

(3)     bubble cap plate tower

(4)     spray tower,        and

(5)     liquid jet scrubber absorbers.

Selective chromatographic absorption of gases on small pellets may offer much higher rates that those achieved in packed towers.

A gas can be sampled by means of suitable absorption reagent.  For this purpose, U-shaped absorbers are used.  These absorbers are filled with a certain measured amount of reagent and fitted with a porous glass partition, so that the air or gas led into them is passed through the reagent solution in the form of fine bubbles thus ensuring intimate contact.  Sampling by means of such absorbers is usually carried out at an average rate of about 100-150 litres per hour of gas stream.  The absorbers may be arranged in series of two or more elements containing two or more different reagent solutions so as to absorb different pollutants successively from the same volume of gas or air sampled.  A typical sampling train is shown in Figure – 1 comprising of an impinger, trap, manometer, flow meter, valve and pump.

By selecting the most suitable absorbent solutions, the gaseous components listed below can be determined in concentrations as low as 0.1 ppm by volume.

1.      Oxides of sulphur

2.      Oxides of nitrogen

3.      Ammonia

4.      Hydrogen sulphide

5.      Hydrochloric acid

6.      Hydrofluoric acid

7.      Hydrocyanic acid

This method can also be used for the determination of ozone, hydrocarbons and organic solvents.

Adsorbers

Adsorption is brought about by aspiring the air or gas to be sampled through adsorption columns containing silica gel, activated charcoal or any other suitable agent.  After adsorption , the different pollutants can be extracted from the column in various ways.  For example, by raising the temperature.

The main difficulty in this method is in selecting a suitable adsorbing medium.  This type of sampling is used especially for ozone and light hydrocarbons.

Condensers

Here the gas stream sampled is cooled in suitable containers, thus bringing about the condensation of the volatile substances present.  As in the case of adsorption devices, here also the condensation traps can be arranged either in series or parallels, at decreasing temperatures.  By using various coolants, e.g., ice, liquid air, or liquid nitrogen the components can be separated by fractional condensation.

This method is used in particular for the sampling of odoriferous substances.

Collectors under Reduced Pressure

For some substances like nitric acid and aldehydes having a high molecular weight, absorption in aqueous solutions is sometimes incomplete.  In such cases, it is preferable to use bottles of known volume for collecting under a pressure reduced to 200 mm Hg or even less.

To do this, the absorbent solution chosen is first introduced into the bottle and the pressure is then reduced.  Then the sample is admitted until the internal and external pressures are equal and the container is shaken continuously so as to ensure maximum absorption.

This method is suitable, for sampling the oxides of N₂.

Plastic Containers

Special polythene bags are commonly used for collecting and transporting large volumes of air.  These bags have the advantage that they can be used for successive analysis of small fractions of the sample taken.  Moreover, polythene is inert with respect to many substances including SO₂ and formaldehyde.  On the other hand, plastic bags are not suitable for collecting and storing aerosol suspensions, because of the possible generation of electrostatic charges, as a result of which the aerosols tend to move towards the walls and condense on them.  Plastic bags have been widely used for grab sampling and sample storage before analysis.

Samplers for Mass-Spectrometric Analysis

Sampling or mass spectrometric analysis can be carried out in various ways.  For example, by compressing the gas sample in a pressure flask so as to concentrate a large quantity of gas in a small volume, or by filling evacuated containers.

calculations

CALCULATIONS

·        If the initial and final calibration flow rates are different, a volume calculated using the highest flow rate should be reported to the laboratory. If compliance is not established using the lowest flow rate, further sampling should be considered.

·        Generally, sampling is conducted at approximately the same temperature and pressure as calibration, in which case no correction for temperature and pressure is required and the sample volume reported to the laboratory is the volume actually measured. Where sampling is conducted at a substantially different temperature or pressure than calibration, an adjustment to the measured air volume may be required depending on the sampling pump used, in order to obtain the actual air volume sampled.

·        The actual volume of air sampled at the sampling site is reported, and used in all calculations.

The laboratory normally does not measure concentrations of gases and vapors directly in parts per million (ppm). Rather, most analytical techniques determine the total weight of contaminant in collection medium. The lab calculates concentration in mg/m3 and converts this to ppm at 25 ⁰C and 760 mm Hg using following Equation. This result is to be compared with the PEL without adjustment for temperature and pressure at the sampling site.

TLV in ppm =  (TLV in mg/m³  ) X (24.45) / (Gram Molecular weight of

                                                                             substance)

OR

TLV in mg/m³ = (TLV in ppm) X (Gram Molecular weight of substance)/24.45

Where:

24.45 =molar volume at 25  C(298 K) and 760 mm Hg

Mwt =molecular weight

NTP =Normal Temperature and Pressure at 25 C and 760 mm Hg

NOTE: When a laboratory result is reported as mg/m3 contaminant, concentrations expressed as ppm (PT) cannot be compared directly to the standards table without converting to NTP.

Adjustment for temperature and pressure: Formula is as bellow:

ppm(PT) = mg/m3 X 24.45/ Mwt X 760/P  X  298/T

·        Time-Weighted Average: The average full shift exposure level calculated by weighing the various concentrations throughout the workday with respect to time.

TWA = C₁T₁ + C₂T₂ + CnTn  / 8 hr

            Where, TWA = Time-weighted average concentrations in ppm/ or mg/m³

                                 C        = Concentration of contaminant during an incremental exposure  

                                        time

                          T       = Time : Incremental Exposure Time

·        Threshold Limit Values for Mixtures :

Ø    Most threshold limit values are developed for a single chemical substance.

Ø    However, the work environment is often composed of multiple chemical exposures both simultaneously and sequentially.

Ø    It is recommended that multiple exposures that comprise such work environments be examined to assure that workers do not experience harmful effects.

Ø    There are several possible modes of chemical mixture interaction.

1)    Additivity occurs when the combined biological effect of the component is equal to the sum of each of the agents given alone.

2)    Synergy occurs where the combined effect is greater than the sum of each agent. 

3)    Antagonism (Reveres Effect) occurs when the combined effect is less.

Ø    The general ACGIH mixture formula applies to the additive model.

NOTE: The guidance contained does not apply to substances in mixed phases.

Ø When two or more hazardous substances have a similar toxicological effect on the same target organ or system, their combined effect, rather than that of either individually, should be given primary consideration. In the absence of information to the contrary, different substances should be considered as additive where the health effect and target organ or system is the same.

That is, if the sum of:  C₁/T₁ + C₂/T₂ +…..Cn /Tn = 1

Where, C₁ indicates the observed atmospheric concentration and T₁ is the corresponding threshold limit)

It is essential that the atmosphere is analyzed both qualitatively and quantitatively for each component present in order to evaluate the threshold limit of the mixture.

Example: Air contains 400 ppm of acetone ( TLV,750 ppm),150 ppm of sec-butyl acetate (TLV,200 ppm) and 100 ppm of methyl ethyl ketone (TLV,200 ppm).

400/750 + 150/200 + 100/200 = 0.53 + 0.75 + 0.5 = 1.78

Threshold limit is exceeded.

Ø Special case when the source of contaminant is a liquid mixture and the atmospheric composition is assumed to be similar to that of the original material, e.g. on a time-weighted average exposure basis, all of the liquid (Solvent) mixture eventually evaporates. When the percent composition ( by weight) of the liquid mixture is known, the TLV s of the constituents must be listed mg/m3.

1/ fa/TLVa+fb/TLVb+fc/TLVc +…fn/TLVn

Example: Liquid contains ( By Weight)

          50% heptan e: TLV 400 ppm or 1600 mg/m3

          30% methyl chloroform : TLV 350 ppm or 1900 mg/m3

          20% perchloroethylene : TLV 50 ppm or 335 mg/m3

          TLV of Mixture = 1/0.5/1600+ 0.3/1900 + 0.2/335

                                   =  1/0.00031 + 0.00016 + 0.0006

                                   =  1/0.00107 =  935 mg/m3

of this mixture:

50% heptane or (935)(0.5) = 468 mg/m3 is heptane

30% methyl chloroform (935)(0.3) =  281 mg/m3 is methyl chloroform

20% perchloroethylen (935)(0.2) = 187 mg/m3 is perchloroethylen

These values can be converted to ppm :

Heptane = 117 ppm

methyl chloroform = 51 ppm

perchloroethylen = 29 ppm

TLV of mixture =  117 + 51 + 29 = 197 ppm

A machine guard means any enclosure, barrier or device constructed to prevent a person or his clothing coming into contact with dangerous parts of the machine.

1.    Point of operation: That area on a machine where material is positioned for processing by the machine and where work is actually being performed on the material.

2.    Zero Mechanical State (ZMS): The mechanical state of a machine in which every power source that can produce a machine member movement has been shut/locked off. This means de-energised, de-pressurised and neutralised condition of the machine or equipment which provides maximum protection against unexpected mechanical movement.

3.    Power off:  The state in which power (electric, pneumatic, hydraulic, atomic etc.) cannot flow to the machine is considered a power-off stage.

4.    Power-locked off: The state in which the device that turns power off is locked in the off position with the padlock of every individual who is working on the machine.

5.    Guarding: Any means of effectively preventing personnel from coming in contact with the moving parts of machinery or equipment which could cause physical harm to the personnel. In case of a power-press, a cover on point of operation (die and punch) is called ‘guard’ while those on other danger zones are called ‘enclosure’ or ‘safeguard’.

               Safety by Guarding is most important as other methods are not always possible. Depending upon the dangerous part, its size, position, speed etc., a guard should be selected. Generally the parts to be guarded fall within three categories :

1.  The prime mover.

2.  Transmission parts from the prime mover to the machine and the transmission parts in the machine itself. It is desirable to minimise them and enclose completely.

3.  Operating parts of a machine, of which the points of dangerous operation need effective guarding.

6.    A machine guard means any enclosure, barrier or device constructed to prevent a person or his clothing coming into contact with dangerous parts of the machine. The point of operation is that part of working machine at which cutting, shaping, forming or any other necessary operation is accomplished. A guard for that part is known as the point of operation guard.

7.    Enclosures: Guarding by fixed physical barriers that are mounted on or around a machine to prevent access to the moving parts.

8.    Fencing: Guarding by means of a locked fence or rail enclosure which restricts access to the machine except by authorised personnel. Enclosures must be a minimum 1 m (42 in) away from the dangerous part of the machine.

9.    Safety by Position or Location: It is a guarding as a result of the physical inaccessibility of a particular hazard under normal operating conditions or use. Words “Safe by location” or “Safe by position” are used to denote safety by distance.

The words “safe by position” are used by Section-21 of the Factories Act. It means the situation (out of reach) or position in such a way that normally it is not possible

Definitions : The Factories Act defines as   under :

          Power means electrical energy or any other form of energy which is mechanically transmitted and is not generated by human or animal agency.

          Prime mover means any engine, motor or other appliance which generates or otherwise provides power.

          Transmission machinery means any shaft, wheel, drum, pulley, system of pulleys, coupling, clutch, driving belt or other appliance or device by which the motion of a prime mover is transmitted to or received by any machinery or appliance.

          Machinery includes prime movers, transmission machinery and all other appliances whereby power is generated, transformed, transmitted or applied. Belt includes any driving strap or rope.

          Maintained means maintained in an efficient state, in efficient working order and in good repair.

Fencing of Machinery : Section-21 requires that every moving part of a prime mover, flywheel, headrace and tailrace of water wheel and turbine, lathe, electric generator, motor, rotary converter, transmission machinery and every dangerous part of any other machinery.

shall be securely constructed, positioned or fenced by safeguards of substantial construction and constantly maintained and kept in position while the parts of machinery they are fencing are in motion or in use.

Work on or near machinery in motion: Section-22 requires that any examination, lubrication, adjusting operation, mounting or shifting of belts while the machinery is in motion shall be carried out by a specially trained adult male worker wearing tight fitting clothing supplied by the occupier and his name shall be recorded in the register in Form No. 8. Such worker shall not handle a belt at a moving pulley unless the belt is not more than 15 cm in width, the pulley is a normal drive (no flywheel or balance wheel), the belt joint is laced or flush with belt, the pulley, joint and pulley rim are in good repair, there is reasonable clearance to work, secure foothold / handhold are provided and any ladder being used is secured fixed or held by a second person. At that time other parts in motion shall be securely fenced to prevent their contact. Woman or young person is not allowed to do such work.

Employment of young persons on dangerous machines : On power presses except hydraulic presses, milling machines, guillotine machines, circular saws and platen printing machines no young person shall work unless he has been fully instructed regarding their dangers and precautions to be observed and has received sufficient training to work on that machine and is under adequate supervision by a person who has a thorough knowledge and experience of that machine (Sec. 23 & Rule 57).

Striking gear and devices for cutting off power:  Suitable striking gear or other efficient device to move driving belts to and from fast and loose pulleys and to prevent the belt from creeping back on to the fast pulley, shall be used and maintained. Driving belts not in use should not rest or ride upon shafting in motion (for which belt hangers are necessary). Other devices for cutting off power are necessary in every work room. Such devices shall be so locked to prevent accidental starting of the machinery.

          Self acting machines : 45 cm or more clear space is necessary from the end of maximum traverse of any self-acting machine or material carried thereon.

Basics of Machine Safeguarding

   Crushed hands and arms,

    Severed fingers, blindness

    The list of possible machinery-related injuries is as long as it is horrifying. There seem to be as many hazards created by moving machine parts as there are types of machines. Safeguards are essential for protecting workers from needless and preventable injuries.

A good rule to remember is: Any machine part, function, or process which many cause injury must be safeguarded. When the operation of a machine or accidental contact with it can injure the operator or others in the vicinity, the hazards must be either controlled or eliminated.

Where Mechanical Hazards Occur
Dangerous moving parts in three basic areas require safeguarding:
The point of operation: that point where work is performed on the material, such as cutting, shaping, boring, or forming of stock.
Power transmission apparatus: all components of the mechanical system which transmit energy to the part of the machine performing the work. These components include flywheels, pulleys, belts, connecting rods, couplings, cams, spindles, chains, cranks, and gears.
Other moving parts: all parts of the machines which move while the machine is working. These can include reciprocating, rotating, and transverse moving parts, as well as feed mechanisms and auxiliary parts of the machine.

Mechanical Motions and Actions

A wide variety of mechanical motions and actions may present hazards to the worker.

The basic types of hazardous mechanical motions and actions are:

Motions

• rotating (including in-running nip points)
• reciprocating
• transversing

Actions

• cutting
• punching
• shearing
• bending

Motions

Dangerous parts to be guarded according to their motions are generally classified as follows :

          Group-1. Rotary Motions : (1) Rotating parts alone viz. shafts, coupling, spindles, projections on moving parts, fly-wheel, saw, gear, knife, cutting tool etc. (2) In-running nips subdivided as (a) Between parts rotating in opposite direction - gears, rolls etc. (b) Between rotating and tangential moving parts - conveyors, belt drives, rack and pinion etc. (c) Between rotating and fixed parts - grinding wheel, paper machine felt or roll, drums, cylinders, worms, spirals  etc.

          Group-2. Reciprocating Sliding Motions : (1) Reciprocating sliding motions and fixed parts (a) Approach type - danger of crushing viz. slides (rams) on power presses and forging hammers, pistons, cross rod of a steam engine and riveting machines (b) Passing types - danger of shearing, viz. planning machine, shaper, spot welder clamping fixtures, guillotine and the shear, power press etc. (2) Single sliding motion - abrasive or sharp nature of objects such as saws or crocodile clips on belts.

          Group-3. Rotating/Sliding Motion : A cam gear having sliding and turning movement etc. falls within this group.

          Group-4. Oscillating Motions : Trapping points between two moving parts or between a moving part and a fixed object viz. a pendulum, crankshaft, closing  platens etc.

Rotating motion can be dangerous; even smooth, slowly rotating shafts can grip clothing, and through mere skin contact force an arm or hand into a dangerous position. Injuries due to contact with rotating parts can be severe.
Common nip points on rotating parts
Nip points are also created between rotating and tangentially moving parts. Some examples would be: the point of contact between a power transmission belt and its pulley, a chain and a sprocket, and a rack and pinion.
 Nip points between rotating elements and parts with longitudinal motions.
Nip points can occur between rotating and fixed parts which create a shearing, crushing, or abrading action. Examples are: spoked handwheels or flywheels, screw conveyors, or the periphery of an abrasive wheel and an incorrectly adjusted work rest. Nip points between rotating machine components; (A - cover removed for clarity.)
Reciprocating motions may be hazardous because, during the back-and-forth or up-and-down motion, a worker may be struck by or caught between a moving and a stationary part. for an example of a reciprocating motion.
 Hazardous reciprocating motion.
Transverse motion (movement in a straight, continuous line) creates a hazard because a worker may be struck or caught in a pinch or shear point by the moving part.
Actions
Cutting action may involve rotating, reciprocating, or transverse motion. The danger of cutting action exists at the point of operation where finger, arm and body injuries can occur and where flying chips or scrap material can strike the head, particularly in the area of the eyes or face. Such hazards are present at the point of operation in cutting wood, metal, or other materials.
Examples of mechanisms involving cutting hazards include bandsaws, circular saws, boring or drilling machines, turning machines (lathes), or milling machines.
Typical punching operation.
Shearing action involves applying power to a slide or knife in order to trim or shear metal or other materials. A hazard occurs at the point of operation where stock is actually inserted, held, and withdrawn.

PRINCIPLES OF MACHINE    GUARDING

Prevent contact: The safeguard must prevent hands, arms, and any other part of a worker's body from making contact with dangerous moving parts. A good safeguarding system eliminates the possibility of the operator or another worker placing parts of their bodies near hazardous moving parts.
Secure: Workers should not be able to easily remove or tamper with the safeguard, because a safeguard that can easily be made ineffective is no safeguard at all. Guards and safety devices should be made of durable material that will withstand the conditions of normal use. They must be firmly secured to the machine.
Protect from falling objects: The safeguard should ensure that no objects can fall into moving parts. A small tool which is dropped into a cycling machine could easily become a projectile that could strike and injure someone.
Create no new hazards: A safeguard defeats its own purpose if it creates a hazard of its own such as a shear (cut off) point, a jagged edge, or an unfinished surface which can cause a laceration. The edges of guards, for instance, should be rolled or bolted in such a way that they eliminate sharp edges.
Create no interference: Any safeguard which impedes a worker from performing the job quickly and comfortably might soon be overridden or disregarded. Proper safeguarding can actually enhance efficiency since it can relieve the worker's apprehensions about injury.
Allow safe lubrication: If possible, one should be able to lubricate the machine without removing the safeguards. Locating oil reservoirs outside the guard, with a line leading to the lubrication point, will reduce the need for the operator or maintenance worker to enter the hazardous area.

Requisite Characteristics (Design principles) of    Guards:

Twelve characteristics, design principles, specifications, basic requirements or good guarding practice for machine guarding are:

1. With its primary purpose of protection, it should also facilitate the work i.e. it should be convenient, reliable and not hampering the work or rate of production.

2. It should fully satisfy the legal provisions and IS prescribed i.e. it should conform the standards, be a complete guard and not incomplete or giving any access to the part to be protected. It should be as close as possible.

3. It should be suitable and effective to the job and the machine. It should not weaken the machine.

4. It should allow for oiling, inspection, adjustment and repair. If it requires opening for this purpose, it should be easily and quickly replaceable.

5. It should withstand wear, shock, vibration and long use with minimum maintenance. If it requires frequent opening and closing, this factor becomes more important.

6. It should be of proper material and construction. It should be well fitted. Fire and corrosion resistant material is preferable.

7. It should be free from self-hazard such as sharp or rough edges, nails, splinters, more opening, noise, vibration etc.

8. If visual watch of operation is necessary, it should be transparent and yet durable.

9. If dusting is possible as in case of machining of wood, rubber, brass, cast iron etc., apart from the guard, dust suction device should also be fitted as a special guarding.

10.    It should be fail-safe i.e. if it fails or breaks it should stop the machine or at least it should give warning (alarm) to stop the machine.

11.    It should be interlocking type i.e. the machine will not start till it is not closed and will stop soon if it is opened.

12.    It should fulfil special requirement depending upon its purpose viz. distance guard should provide sufficient protective distance, trip guard must immediately trip the machine etc.

1. 

Industrial Noise

Industrial Noise refers to noise that is created in the factories which is jarring and unbearable. Sound becomes noise only it becomes unwanted and when it becomes more than that it is referred to as "noise pollution". Heavy industries like shipbuilding and iron and steel have long been associated with Noise Induced Hearing Loss (NIHL). 

Industrial Noise Pollution

This is posing to be a big challenge with very passing day and is a threat to safety and health of the people who are working in the industry and common people as well. It has been scientifically proved that noise more than 85 decibels can cause hearing impairment and does not meet the standards set for healthy working environment. Moreover it can also cause accidents. The problem has been viewed and analyzed from all the perspectives but the solution probably is not so easy to achieve since there is a lot of contradiction between legislation, guidance and documents.Industrial Noise resulting to noise pollution has many reasons such as industries being close to human habitats which prevents the noise from decaying before it reaches human ear. 




Effects of Industrial Noise Pollution

It has already been stated that continuous exposure to noise pollution leads to hearing impairment but it has various other effects as well which are as follows:

• It can result into increase in blood pressure
• Increased stress
• Fatigue
• Stomach ulcers
• vertigo
• Headaches.
• Sleep disturbance
• Annoyance
• Speech Problems
• Dysgraphia, which means writing learning impairment
• Aggression
• Anxiety
• Withdrawal

Industrial Noise adversely affects the workers and they suffer from various health problems as I have listed above. High volume leads to increased adrenaline levels, which leads to the constriction of blood vessels, which normally happens when the individual is tensed, afraid, anxious or extremely happy and excited. The work pressure and the noise pollution both lead to a fairly typical situation, which leads to clinical as well as psychological stress. The blood pressure, due to the constriction of blood vessels (vasoconstriction), remains high for the major part of the day. The human dislike towards anything that is not pleasant, yet compelling leads to emotional stress and depression which is a term for a quite a severe situation. Statistically there is a rise in the number of workers dying of cardiac arrests and cerebral attacks is on an increase considerably due to industrial noise pollution in railway yards, factories etc.

Some people also suffer from headaches, which decrease their efficiency levels and hamper the quality of their work. That leads to crises in workplace as well as home. Workers are always agitated and excited that result into carelessness. Workers also become fatigued and in some cases over fatigued which should ring the alarm for organizations that want to grow. The worst part of Industrial Noise pollution is it affects the unborn baby in a womb and that too in the early days after conception since the fetus is sensitive to sounds and high decibels affects the growth of its organs.

The problems that the Industrial workers face are sleep disorders and behavioral changes. They experience increased levels of stress. They fail to achieve harmony thus leading to a lot of minor psychological problems, which are too common to be noticed. They are irritated and annoyed; therefore fail to interact with a person around them and this gradually leads them to become "loners". They withdraw from the society and some in extreme circumstances might have "tremors", speech problems and many other behavioral problems. It is high time that the rules and regulations that are already made should be applied and followed so that we can cope with the ever-increasing problem of noise pollution that is concentrated in the industry environment.

Employee Participation

Employee Participation (Health & Safety)

A fundamental ingredient in reducing the rate of accidents and deaths in New Zealand workplaces is to ensure workers play an active and equal role in all areas of Health & Safety management.  Almost without exception studies and research, whether they’re union funded or independent reach the same conclusion.  That is that effective Health & Safety can only be achieved if workers participate in the development, implementation, enforcement and monitoring of health and safety programmes.

While this common feature runs through most successful H&S systems the systems themselves vary considerably.  Obviously factors such as the size of the organisation, available resources and legislative framework will influence the form of any given H&S programme takes. 

Effective employee participation means more than worker representatives on H&S committees, although this is obviously very important. The basic premise is that workers have a greater knowledge of the health and safety issues involved in their job than management and union officials do.  Therefore the best solutions will only be achieved if an environment is created where workers are actively encouraged to identify and report hazards.

We are beginning to recognise more and more workplace hazards.  Many of them are not unique to a given industry.  It is important that unions provide information and training on such hazards.  For example, stress and fatigue, workplace violence and drug and alcohol impairment are all examples of hazards that are sometimes not immediately recognised.  It is important therefore that employee representatives are provided with all the necessary information and support to promote these issues as genuine health and safety concerns that need to be addressed through whatever H&S management system is in place.

There are other opportunities for workers to be actively involved in health and safety.  For example, workers in companies that are part of the ACC partnership programme need to be involved in areas such as the auditing process.  It is a requirement that participating companies involve workers in health and safety but the reality is that very often it does not happen. 

Non-compliance with Partnership requirements should be partially addressed with the amendments to the HSE Act.

Participation means Unions

The April 1999 issue of Hazard Magazine reported on an American study on “Factors that support effective worker participation in heath and safety”.

The key findings of the report were,

1.    Effective strategies for involving workers appear to be conditional on a number of variables, most importantly on worker activism and the effective use of formal union negotiations. 

2.    Union education and training is also a critical variable in achieving effective arrangements for worker participation. 

3.    The probability of an OSH inspection, duration of the inspection, and sized of the penalties were significantly higher in unionised work sites.

The report highlights the important role of unions in assisting workers in accessing and understanding health and safety information, negotiating agreements that protect workers who refuse dangerous work and confront management about their health and safety concerns. 

The report is consistent with other studies that emphasize the role of unions in shaping opportunities for effective worker participation.  The challenge for unions is to develop strategies that will ensure workers are both given the opportunity to play an active role in health and safety and make the most of the opportunity.  This means that workers need to be playing an active role at all levels of health and safety.  This includes industry level (National Safer Industry Groups) and enterprise level (H&S committees and H&S representatives).  Unions need to provide the training, information and ongoing support for workers. 

It is important to recognise that throughout the often tragic history of worker health and disease, the worker played a primary role as the basis of every significant improvement in legislation, factory inspection compensation, correction and prevention.

The Canadian Ministry of Labour conducted a survey in 1993 that reached the conclusion that “union supported health and safety committees have a significant impact in reducing injury rate”.

The Ontario Workplace Health and Safety Agency found that 78-79 per cent of unionised workplaces reported high compliance with health and safety legislation while only 54-61 per cent of non-unionised workplaces reported such compliance. 

Research in the United Kingdom, Canada, Australia and the United States all reach the same general conclusion.  That is that unionised workplaces with effective worker participation in health and safety are far safer than non-union workplaces with poor worker participation. 

There are numerous examples and models for effective worker participation.  It is not practicable to go into any great detail in this paper.  However, it is important to identify the different steps at which workers must be fully involved.  By way of example of the different stages workers should be involved in.

Policy

From the beginning workers need to be involved in developing the overall objectives of the H&S programme.

Organising

Workers need to take responsibility for specific tasks, training and communication.

Planning

Workers need to be a part of designing and implementation of the programmes.

Measurement

It is important that workers are continually monitoring and striving to improve the agreed H&S programme

Audit & Review

The purpose of the audit process is to identify any existing or potential flaws in the programme.  Therefore it is important that workers are involved in this process. 

The role of the Union is to provide all the support, information and training that workers need to properly and confidently participate in the management of health and safety.